Hearing Protection: Your Body's Fight or Flight Response Helping You

Monday, June 7th, 2010

A throwback to caveman days, we carry that "fight or flight" ability with us today, though instead of saber-toothed tigers, we're more inclined to be dodging cars crossing the street. Even so, the ability to instantaneously determine when to fight and when to flee is actually a hormonal response. Hormones are chemicals that are produced by the body. We have lots of them: estrogen, testosterone, adrenaline, FSH, insulin – the body's system produces hormones all day every day.

For example, when you perceive a threat to yourself or others your body chemistry changes which causes the adrenal glands to produce adrenaline that increases your heart rate, dilates the pupils and prepares you to fight or hit the bricks. The body recognizes danger and shifts you into the fight or flight mode. (Most of the time we wisely flee these days from potential dangers. We've gotten smarter, learned from the mistakes made by our predecessors and no longer have to worry about becoming lunch for a saber-toothed tiger.)

A recently published study indicates that the human ear responds in a similar fashion to the fight or flight hormonal reaction that body experiences when faced with danger, stress or anxiety. In other words, when the ears are exposed to loud noise (stress to our hearing), the body chemistry actually changes to protect the delicate mechanism that we use to hear the world around us.

The study focused on a specific hormone receptor produced by the brain called corticotrophin-releasing factor, CRF for short. CRF is produced by a gland inside the brain called the hypothalamus. It's a tiny member of the body's endocrine system, responsible for producing all those hormones, enzymes, peptides and other molecules that keep the body operating in good health.

This study demonstrates for the first time that the cochlea – a small, snail-shaped organ that's part of the hearing system, alerts the brain to produce CRF to protect itself when exposed to loud noise. You don't have to think about it – it just happens, just as the fight or flight reaction kicks in whenever we're faced with perceived danger or stress.

Good News, Right?

Well, yes and no. It's good news that the body tries to protect itself from loud noise, but it's not so good if we ignore the dangers that long-term exposure to loud noise can do to hearing health. The fact is, even though the body's chemistry changes when it's exposed to loud noise, we still live in a very noisy world.

Oh sure, you may wear protective eye wear when using your favorite chain saw but do you have ear plugs in – even if you're only cutting a branch or two? Hearing loss is cumulative. If you're plugged into your music player 12 hours a day, if you work on a factory floor or in a loud, noisy office or restaurant, your ears are bombarded by the constant drone of noise. You may not be aware of it but your ears are. And so's that hypothalamus of yours trying to pump out enough CRF to protect your hearing mechanism.

What can you do to protect the hearing you've got (because once it's gone it's almost always gone for good)? Go proactive. Increase your awareness of the noise around you. And take steps to prevent long-term exposure to loud noise. It's not hard, you know, and the pay off is better hearing longer.

Protecting Against Hearing Loss

If convenience and cost are your top priorities, pick up some moldable foam ear plugs at the local pharmacy.

If you plan on running that chain saw all day, or you work on a noisy factory assembly line, consider buying a pair of "over-the-ear ear muffs." They're comfortable, even when you wear them all day long, and they come in two varieties.

You can purchase ear muffs that block out all noise or, if you spend a little more, you can purchase "hear-through ear muffs". These allow you to hear your floor manager's directions while still blocking out the extraneous noise that surrounds you.

Now, what about iPods, MP3 players and other portable sound systems? First, scroll down the volume. Second, give your ears a break. Constant exposuire weakens the hearing system and if given time to recover the hearing system can repair itself. Finally, toss out the ear buds that came with your MP3 player and buy a pair of over-the-ear noise-canceling headphones. These headphones block out a lot of the background noise, allowing you to hear more music at a lower volume.

And, if you really want to go all out, consider buying yourself a pair of custom made earplugs. These earplugs are custom made to your ears and can even be fit with specific types of filters depending upon what type of noise you want to filter. For example musicians utilize a filter that does not distort the sound quality of the music.

So, the human body does all it can to protect your hearing, but the human body can only do so much. The best defense against hearing loss is to take a pro-active stance toward reducing the amount of noise around you and protecting the hearing you have through the use of hearing protection devices that reduce the level of noise you hear – even when you're surrounded by LOUD noise.